sub is_rotatable{ #23456789 123456789 123456789 123456789 123456789 1234 (local$_=$_[0])=~y/0125689347/0152968/;reverse eq$_[0] } #### P:\test>type junk.pl sub is_rotatable{ #23456789 123456789 123456789 123456789 123456789 1234 (local$_=$_[0])=~y/0125689347/0152986/;reverse eq$_[0] } printf "%s %s rotatable\n", $_, is_rotatable( $_ ) ? 'is' : 'not' for 33, 131, 141, 171, 25696925, 101, 88; P:\test>junk 33 not rotatable 131 not rotatable 141 not rotatable 171 not rotatable 25696925 is rotatable 101 is rotatable 88 is rotatable #### P:\test>type junk.pl sub is_rotatable{ #23456789 123456789 123456789 123456789 12345678 (local$_=$_[0])=~y/2569347/5296/;reverse eq$_[0] } printf "%s %s rotatable\n", $_, is_rotatable( $_ ) ? 'is' : 'not' for 33, 131, 141, 171, 25696925, 101, 88; P:\test>junk 33 not rotatable 131 not rotatable 141 not rotatable 171 not rotatable 25696925 is rotatable 101 is rotatable 88 is rotatable